[17.06] backport (cli) If docker swarm ca is not called with the --rotate flag, warn if other flags are passed

[andrewhsu]

Backport fix (each PR has just one git commit):

• If docker swarm ca is not called with the --rotate flag, warn if other flags are passed docker/cli#207 If docker swarm ca is not called with the --rotate flag, warn if other flags are passed
• Fix warning in docker CLI when swarm ca is called with flags other than --rotate docker/cli#328 Fix warning in docker CLI when swarm ca is called with flags other than --rotate

With cherry-pick of docker/cli@32b43bc and docker/cli@4615c92:

$ git cherry-pick -s -x -Xsubtree=components/cli 32b43bc 4615c92

Conflict with components/cli/cli/command/swarm/ca_test.go in that the docker/cli@4615c92 cherry-pick wanted to modify it and it did not exist on the 17.06 branch. Resolved the conflict by not apply the diff to that file.

[andrewhsu]

@cyli when you get the chance can you have a look at this backport?

[cyli]

@andrewhsu That definitely matches the change in the docker/cli#207, however I noticed a comment indicating a bug in that partiuclar fix, so have openned docker/cli#328.

The only change is to change that second flagCACert to flagCertExpiry. I'm not sure how to cherry-pick that change, since there was a refactor between docker/cli#207, and docker/cli#328.

[thaJeztah]

I just merged docker/cli#328 - if it doesn't apply cleanly, perhaps just add a second commit to the PR to perform the fix

[andrewhsu]

I brought in the commit from docker/cli#328:

$ git cherry-pick -s -x -Xsubtree=components/cli 4615c92f

Conflict with components/cli/cli/command/swarm/ca_test.go in that the docker/cli@4615c92 cherry-pick wanted to modify it and it did not exist on the 17.06 branch. Resolved the conflict by not apply the diff to that file.

[cyli]

LGTM on green, thanks @andrewhsu and @thaJeztah!

[thaJeztah]

LGTM